Walk-behind compaction rollers are used to compact soil and asphalt in order to provide a firm foundation for structural building, to reduce future settlement of soil, or to compact asphalt for pathway, road, and parking lot construction. Such machines are commonly controlled by a single operator who follows behind the machine to direct the machine's travel direction and actuate its vibration control(s). Commonly, a control arm extends rearwardly from the machine and provides the mechanical advantage to allow the operator to physically manipulate the direction of travel of the machine. Such machines may have one drum (single-rum) or two (dual-drum) drums acting as compaction surface(s).
One method to control the speed and direction (forward and/or rearward) of such machines is with a control lever that is supported at a rearward end portion of the control arm and whose position relative to the control arm actuates forward and reverse self-propelled travel of the machine. As alluded to above, such machines can be steered with a lateral force applied to the control arm to effectuate turning of the machine.
Commonly, when the control lever is released, a spring force returns the control lever into the neutral position, and the machine ceases all travel. Such machines are also commonly provided with a button or plunger that is disposed on a rearward distal end of the control arm and which interacts with the control associated with manipulation of the control lever. Depression of the button from behind the machine can suspend travel of the rolling machine altogether or at least prevent rearward propulsion of the machine while permitting forward propulsion. Such a configuration prevents an operator from being pinned between the machine and an obstacle behind the machine.
These machines are relatively heavy, making turning of the machine difficult. As mentioned above, the length of the control arm is set to obtain leverage sufficient to allow a single operator to turn the machine by imparting lateral directional forces of a manageable magnitude to the control arm.
In addition to the physical interaction of the operator with the control arm and the control lever, desired operation of the compaction roller requires the operator be able to readily visually inspect the operating environment to assess the speed and direction of travel relative to, for instance, areas already compacted, obstructions such as trench walls, other personnel, equipment, grade stakes or markings, already set formwork, etc. Because the rearward orientation of the control arm and control lever places the operator in a position that is substantially directly behind the compaction roller, the compaction roller can substantially hinder the operator's ability to visually inspect the operating environment.
Many prior manually operated compaction milers are provided with a single control handle on the control arm that is oriented along the centerline or in-plane with the machine's centerline. One such configuration is shown in FIG. 24, in which a visible area is denoted by lines 30 relative to the underlying compaction roller 32. Such a configuration requires the operator to frequently reposition his body relative to the control arm 34 and the control lever 36 in order to achieve a desired orientation required to visually inspect the longitudinal edges 38 that extend along generally opposite lateral sides of the underlying compaction roller 32. In confined work environments, cornering and edge following can result in the operator attaining positions relative to the control arm 34 and control lever 36 that detracts from the operator's overall ability to manipulate the compaction roller 32 to effectuate the desired turning and travel direction control of the compaction roller.
The position and orientation of the control lever relative to the control arm of many manually steered compaction rollers are ill-suited to allow the operator to attain various operating positions relative to the control arm and the control lever to provide the desired physical interaction with both the control arm and the control lever. They also provide for only limited positional association of the operator relative to the control arm to improve the visibility associated with operation of the compaction roller while maintaining a desired interaction of the operator with the control arm and the control lever. That is, the operators of such devices must commonly shuffle their left and right hands into and out of interaction with the control lever and/or the control arm or control handles to achieve the desired visibility and operator physical positioning with respect to the compaction roller controls to achieve the desired changes to the operating status and direction of travel of the compaction roller.
There is therefore a need for an improved arrangement for controlling operation of manually steered compaction roller machines from various positions relative to the control lever and control arm.